US 8,948,289 B2Granted

Method and device for codebook generation and downlink signal transmission in a wireless communication system supporting multiple antennas

AssigneeLG Electronics Inc.

InventorsHyun Soo Ko, Moon Il Lee, Jae Hoon Chung, Bin Chul Ihm, Seung Hyun Kang

Life of this patent

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Abstract

The present invention relates to a method in which a base station transmits a downlink signal using 8 antennas may comprise the steps of: mapping a downlink signal to N (1≦N≦4) layers; precoding the signal mapped to the N layers, by using a specific precoding matrix selected from a pre-stored codebook; subjecting the precoded signal to processing for OFDM symbol generation; and transmitting OFDM symbols through 8 antennas. The pre-stored codebook may comprise precoding matrices for the respective ranks corresponding to N, the pre-stored codebook may consist of 16 codebook indexes, and a portion of the precoding matrices for high ranks in the 16 codebook indexes may be generated from the precoding matrices for low ranks.

Claims8

Dependent claims

A method of transmitting a downlink signal, which is transmitted by a base station using 8 antennas, comprising the steps of:

mapping the downlink signal to N layers (1≦N≦4);
precoding the signal mapped to the N layers using a specific precoding matrix selected from a previously stored codebook;
performing a processing for OFDM symbol configuration on the precoded signal;
and
transmitting OFDM symbol via the 8 antennas,
wherein the previously stored codebook comprises precoding matrixes respectively corresponding to N ranks,
wherein the previously stored codebook comprises 16 codebook indexes,
wherein a portion of the precoding matrix for a high rank for each of the 16 codebook indexes comprises the precoding matrix for a low rank,
wherein the previously stored codebook comprises
Codebook
Index
Rank 1
Rank 2
Rank3
1
[W1(1)]
[W1(1) W1(2)]
[W1(1) W1(2) W1(3)]
2
[W1(2)]
[W1(2) W1(3)]
[W1(2) W1(3) W1(4)]
3
[W1(3)]
[W1(3) W1(4)]
[W1(3) W1(4) W1(5)]
4
[W1(4)]
[W1(4) W1(5)]
[W1(4) W1(5) W1(6)]
5
[W1(5)]
[W1(5) W1(6)]
[W1(5) W1(6) W1(7)]
6
[W1(6)]
[W1(6) W1(7)]
[W1(6) W1(7) W1(8)]
7
[W1(7)]
[W1(7) W1(8)]
[W1(7) W1(8) W1(1)]
8
[W1(8)]
[W1(8) W1(1)]
[W1(8) W1(1) W1(2)]
9
[W4(1)]
[W2(1) W2(2)]
[W2(1) W2(2) W4(2)]
10
[W4(2)]
[W2(3) W2(4)]
[W2(3) W2(4) W4(4)]
11
[W4(3)]
[W2(5) W2(6)]
[W2(5) W2(6) W4(6)]
12
[W4(4)]
[W2(7) W2(8)]
[W2(7) W2(8) W4(8)]
13
[W4(5)]
[W3(1) W3(2)]
[W3(1) W3(2) W4(1)]
14
[W4(6)]
[W3(3) W3(4)]
[W3(3) W3(4) W4(3)]
15
[W4(7)]
[W3(5) W3(6)]
[W3(5) W3(6) W4(5)]
16
[W4(8)]
[W3(7) W3(8)]
[W3(7) W3(8) W4(7)]
Codebook
Index
Rank 4
1
[W1(1) W1(2) W1(3) W1(4)]
2
[W1(2) W1(3) W1(4) W1(5)]
3
[W1(3) W1(4) W1(5) W1(6)]
4
[W1(4) W1(5) W1(6) W1(7)]
5
[W1(5) W1(6) W1(7) W1(8)]
6
[W1(6) W1(7) W1(8) W1(1)]
7
[W1(7) W1(8) W1(1) W1(2)]
8
[W1(8) W1(1) W1(2) W1(3)]
9
[W2(1) W2(2) W2(3) W2(4)]
10
[W2(3) W2(4) W2(5) W2(6)]
11
[W2(5) W2(6) W2(7) W2(8)]
12
[W2(7) W2(8) W2(1) W2(2)]
13
[W3(1) W3(2) W3(3) W3(4)]
14
[W3(3) W3(4) W3(5) W3(6)]
15
[W3(5) W3(6) W3(7) W3(8)]
16
[W3(7) W3(8) W3(1) W3(2)],
wherein W1, W2, W3 and W4 comprise
W
1
=
DFT
8
×
8
W
2
=
P
T
⁡
[
D
1
0
0
D
1
]
⁢
P
,
⁢
where
⁢
⁢
D
1
=
DFT
4
×
4
W
3
=
P
T
⁡
[
D
2
0
0
D
2
]
⁢
P
,
⁢
where
⁢
⁢
D
2
=
diag
⁡
[
1
,
ⅇ
π
⁢
⁢
j
/
4
,
ⅇ
π
⁢
⁢
j
/
2
,
ⅇ
3
⁢
π
⁢
⁢
j
/
4
]
⁢
DFT
4
×
4
,
and
W
4
=
P
T
⁢
W
1
,
wherein it is P=[e1 e5 e2 e6 e3 e7 e4 e8],
wherein ek (1≦k≦8) is a unitary vector having a non-zero value for a k-th element,
wherein DFT4×4 and DFT8×8 comprise
DFT
4
×
4
=
1
4
⁡
[
1
1
1
1
1
j
-
1
-
j
1
-
1
1
-
1
1
-
j
-
1
j
]
and
DFT
8
×
8
=
1
8
⁡
[
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
1
w
2
w
3
w
4
w
5
w
6
w
7
w
0
w
2
w
4
w
6
w
8
w
10
w
12
w
14
w
0
w
3
w
6
w
9
w
12
w
15
w
18
w
21
w
0
w
4
w
8
w
12
w
16
w
20
w
24
w
28
w
0
w
5
w
10
w
15
w
20
w
25
w
30
w
35
w
0
w
6
w
12
w
18
w
24
w
30
w
36
w
42
w
0
w
7
w
14
w
21
w
28
w
35
w
42
w
49
]
where
,
⁢
w
=
ⅇ
-
2
⁢
π
⁢
⁢
ⅈ
8
,
respectively.

407 more elements

A method of receiving a downlink signal, which is received from a base station by a user equipment, comprising the steps of:

receiving the downlink signal transmitted via 8 antennas by being mapped to N layers (1≦N≦4) from the base station;
and
processing the received signal using a specific precoding matrix selected from a previously stored codebook,
wherein the previously stored codebook comprises precoding matrixes respectively corresponding to N ranks,
wherein the previously stored codebook comprises 16 codebook indexes,
wherein a portion of the precoding matrix for a high rank for each of the 16 codebook indexes comprises the precoding matrix for a low rank,
wherein the previously stored codebook comprises
Codebook
Index
Rank 1
Rank 2
Rank3
Rank 4
1
[W1(1)]
[W1(1) W1(2)]
[W1(1) W1(2) W1(3)]
[W1(1) W1(2) W1(3) W1(4)]
2
[W1(2)]
[W1(2) W1(3)]
[W1(2) W1(3) W1(4)]
[W1(2) W1(3) W1(4) W1(5)]
3
[W1(3)]
[W1(3) W1(4)]
[W1(3) W1(4) W1(5)]
[W1(3) W1(4) W1(5) W1(6)]
4
[W1(4)]
[W1(4) W1(5)]
[W1(4) W1(5) W1(6)]
[W1(4) W1(5) W1(6) W1(7)]
5
[W1(5)]
[W1(5) W1(6)]
[W1(5) W1(6) W1(7)]
[W1(5) W1(6) W1(7) W1(8)]
6
[W1(6)]
[W1(6) W1(7)]
[W1(6) W1(7) W1(8)]
[W1(6) W1(7) W1(8) W1(1)]
7
[W1(7)]
[W1(7) W1(8)]
[W1(7) W1(8) W1(1)]
[W1(7) W1(8) W1(1) W1(2)]
8
[W1(8)]
[W1(8) W1(1)]
[W1(8) W1(1) W1(2)]
[W1(8) W1(1) W1(2) W1(3)]
9
[W4(1)]
[W2(1) W2(2)]
[W2(1) W2(2) W4(2)]
[W2(1) W2(2) W2(3) W2(4)]
10
[W4(2)]
[W2(3) W2(4)]
[W2(3) W2(4) W4(4)]
[W2(3) W2(4) W2(5) W2(6)]
11
[W4(3)]
[W2(5) W2(6)]
[W2(5) W2(6) W4(6)]
[W2(5) W2(6) W2(7) W2(8)]
12
[W4(4)]
[W2(7) W2(8)]
[W2(7) W2(8) W4(8)]
[W2(7) W2(8) W2(1) W2(2)]
13
[W4(5)]
[W3(1) W3(2)]
[W3(1) W3(2) W4(1)]
[W3(1) W3(2) W3(3) W3(4)]
14
[W4(6)]
[W3(3) W3(4)]
[W3(3) W3(4) W4(3)]
[W3(3) W3(4) W3(5) W3(6)]
15
[W4(7)]
[W3(5) W3(6)]
[W3(5) W3(6) W4(5)]
[W3(5) W3(6) W3(7) W3(8)]
16
[W4(8)]
[W3(7) W3(8)]
[W3(7) W3(8) W4(7)]
[W3(7) W3(8) W3(1) W3(2)],
wherein W1, W2, W3 and W4 comprise
W
1
=
DFT
8
×
8
W
2
=
P
T
⁡
[
D
1
0
0
D
1
]
⁢
P
,
⁢
where
⁢
⁢
D
1
=
DFT
4
×
4
W
3
=
P
T
⁡
[
D
2
0
0
D
2
]
⁢
P
,
⁢
where
⁢
⁢
D
2
=
diag
⁡
[
1
,
ⅇ
π
⁢
⁢
j
/
4
,
ⅇ
π
⁢
⁢
j
/
2
,
ⅇ
3
⁢
π
⁢
⁢
j
/
4
]
⁢
DFT
4
×
4
,
and
W
4
=
P
T
⁢
W
1
,
wherein it is P=[e1 e5 e2 e6 e3 e7 e4 e8],
wherein ek (1≦k≦8) is a unitary vector having a non-zero value for a k-th element,
wherein DFT4×4 and DFT8×8 comprise
DFT
4
×
4
=
1
4
⁡
[
1
1
1
1
1
j
-
1
-
j
1
-
1
1
-
1
1
-
j
-
1
j
]
and
DFT
8
×
8
=
1
8
⁡
[
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
1
w
2
w
3
w
4
w
5
w
6
w
7
w
0
w
2
w
4
w
6
w
8
w
10
w
12
w
14
w
0
w
3
w
6
w
9
w
12
w
15
w
18
w
21
w
0
w
4
w
8
w
12
w
16
w
20
w
24
w
28
w
0
w
5
w
10
w
15
w
20
w
25
w
30
w
35
w
0
w
6
w
12
w
18
w
24
w
30
w
36
w
42
w
0
w
7
w
14
w
21
w
28
w
35
w
42
w
49
]
where
,
⁢
w
=
ⅇ
-
2
⁢
π
⁢
⁢
ⅈ
8
,
respectively.

387 more elements

A base station device, which transmitting a downlink signal, comprising:

8 antennas configured for signal transmission and reception;
a memory storing a codebook used to transmit a signal mapped to at least one layer via the 8 antennas;
and
a processor configured to process a transmission of the downlink signal by being connected to the antennas and the memory, the processor comprising:
a layer mapper mapping the downlink signal to N layers (1≦N≦4);
a precoder precoding the signal mapped to the N layers using a specific precoding matrix selected from a previously stored codebook;
and
a transmitting module performing a processing for OFDM symbol configuration on the precoded signal, the transmitting module transmitting the processed signal via the 8 antennas,
wherein the codebook comprises precoding matrixes respectively corresponding to N ranks,
wherein the codebook comprises 16 codebook indexes,
wherein a portion of the precoding matrix for a high rank for each of the 16 codebook indexes comprises the precoding matrix for a low rank,
wherein the codebook comprises
Codebook
Index
Rank 1
Rank 2
Rank3
Rank 4
1
[W1(1)]
[W1(1) W1(2)]
[W1(1) W1(2) W1(3)]
[W1(1) W1(2) W1(3) W1(4)]
2
[W1(2)]
[W1(2) W1(3)]
[W1(2) W1(3) W1(4)]
[W1(2) W1(3) W1(4) W1(5)]
3
[W1(3)]
[W1(3) W1(4)]
[W1(3) W1(4) W1(5)]
[W1(3) W1(4) W1(5) W1(6)]
4
[W1(4)]
[W1(4) W1(5)]
[W1(4) W1(5) W1(6)]
[W1(4) W1(5) W1(6) W1(7)]
5
[W1(5)]
[W1(5) W1(6)]
[W1(5) W1(6) W1(7)]
[W1(5) W1(6) W1(7) W1(8)]
6
[W1(6)]
[W1(6) W1(7)]
[W1(6) W1(7) W1(8)]
[W1(6) W1(7) W1(8) W1(1)]
7
[W1(7)]
[W1(7) W1(8)]
[W1(7) W1(8) W1(1)]
[W1(7) W1(8) W1(1) W1(2)]
8
[W1(8)]
[W1(8) W1(1)]
[W1(8) W1(1) W1(2)]
[W1(8) W1(1) W1(2) W1(3)]
9
[W4(1)]
[W2(1) W2(2)]
[W2(1) W2(2) W4(2)]
[W2(1) W2(2) W2(3) W2(4)]
10
[W4(2)]
[W2(3) W2(4)]
[W2(3) W2(4) W4(4)]
[W2(3) W2(4) W2(5) W2(6)]
11
[W4(3)]
[W2(5) W2(6)]
[W2(5) W2(6) W4(6)]
[W2(5) W2(6) W2(7) W2(8)]
12
[W4(4)]
[W2(7) W2(8)]
[W2(7) W2(8) W4(8)]
[W2(7) W2(8) W2(1) W2(2)]
13
[W4(5)]
[W3(1) W3(2)]
[W3(1) W3(2) W4(1)]
[W3(1) W3(2) W3(3) W3(4)]
14
[W4(6)]
[W3(3) W3(4)]
[W3(3) W3(4) W4(3)]
[W3(3) W3(4) W3(5) W3(6)]
15
[W4(7)]
[W3(5) W3(6)]
[W3(5) W3(6) W4(5)]
[W3(5) W3(6) W3(7) W3(8)]
16
[W4(8)]
[W3(7) W3(8)]
[W3(7) W3(8) W4(7)]
[W3(7) W3(8) W3(1) W3(2)],
wherein W1, W2, W3 and W4 comprise
W
1
=
DFT
8
×
8
W
2
=
P
T
⁡
[
D
1
0
0
D
1
]
⁢
P
,
⁢
where
⁢
⁢
D
1
=
DFT
4
×
4
W
3
=
P
T
⁡
[
D
2
0
0
D
2
]
⁢
P
,
⁢
where
⁢
⁢
D
2
=
diag
⁡
[
1
,
ⅇ
π
⁢
⁢
j
/
4
,
ⅇ
π
⁢
⁢
j
/
2
,
ⅇ
3
⁢
π
⁢
⁢
j
/
4
]
⁢
DFT
4
×
4
,
and
W
4
=
P
T
⁢
W
1
,
wherein it is P=[e1 e5 e2 e6 e3 e7 e4 e8],
wherein ek (1≦k≦8) is a unitary vector having a non-zero value for a k-th element,
wherein DFT4×4 and DFT8×8 comprise
DFT
4
×
4
=
1
4
⁡
[
1
1
1
1
1
j
-
1
-
j
1
-
1
1
-
1
1
-
j
-
1
j
]
and
DFT
8
×
8
=
1
8
⁡
[
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
1
w
2
w
3
w
4
w
5
w
6
w
7
w
0
w
2
w
4
w
6
w
8
w
10
w
12
w
14
w
0
w
3
w
6
w
9
w
12
w
15
w
18
w
21
w
0
w
4
w
8
w
12
w
16
w
20
w
24
w
28
w
0
w
5
w
10
w
15
w
20
w
25
w
30
w
35
w
0
w
6
w
12
w
18
w
24
w
30
w
36
w
42
w
0
w
7
w
14
w
21
w
28
w
35
w
42
w
49
]
where
,
⁢
w
=
ⅇ
-
2
⁢
πⅈ
8
,
respectively.

389 more elements

A user equipment device, which receives a downlink signal from a base station, comprising:

a signal transceiving antenna;
a memory storing a codebook used to receive the downlink signal transmitted via 8 antennas by being mapped to N layers (1≦N≦4) from the base station;
and
a processor processing a reception of the downlink signal by being connected to the antenna and the memory, the processor configured to process the received signal using a specific precoding matrix selected from a codebook stored in the memory,
wherein the codebook comprises precoding matrixes respectively corresponding to N ranks,
wherein the previously stored codebook comprises 16 codebook indexes,
wherein a portion of the precoding matrix for a high rank for each of the 16 codebook indexes comprises the precoding matrix for a low rank,
wherein the previously stored codebook comprises
Codebook
Index
Rank 1
Rank 2
Rank3
Rank 4
1
[W1(1)]
[W1(1) W1(2)]
[W1(1) W1(2) W1(3)]
[W1(1) W1(2) W1(3) W1(4)]
2
[W1(2)]
[W1(2) W1(3)]
[W1(2) W1(3) W1(4)]
[W1(2) W1(3) W1(4) W1(5)]
3
[W1(3)]
[W1(3) W1(4)]
[W1(3) W1(4) W1(5)]
[W1(3) W1(4) W1(5) W1(6)]
4
[W1(4)]
[W1(4) W1(5)]
[W1(4) W1(5) W1(6)]
[W1(4) W1(5) W1(6) W1(7)]
5
[W1(5)]
[W1(5) W1(6)]
[W1(5) W1(6) W1(7)]
[W1(5) W1(6) W1(7) W1(8)]
6
[W1(6)]
[W1(6) W1(7)]
[W1(6) W1(7) W1(8)]
[W1(6) W1(7) W1(8) W1(1)]
7
[W1(7)]
[W1(7) W1(8)]
[W1(7) W1(8) W1(1)]
[W1(7) W1(8) W1(1) W1(2)]
8
[W1(8)]
[W1(8) W1(1)]
[W1(8) W1(1) W1(2)]
[W1(8) W1(1) W1(2) W1(3)]
9
[W4(1)]
[W2(1) W2(2)]
[W2(1) W2(2) W4(2)]
[W2(1) W2(2) W2(3) W2(4)]
10
[W4(2)]
[W2(3) W2(4)]
[W2(3) W2(4) W4(4)]
[W2(3) W2(4) W2(5) W2(6)]
11
[W4(3)]
[W2(5) W2(6)]
[W2(5) W2(6) W4(6)]
[W2(5) W2(6) W2(7) W2(8)]
12
[W4(4)]
[W2(7) W2(8)]
[W2(7) W2(8) W4(8)]
[W2(7) W2(8) W2(1) W2(2)]
13
[W4(5)]
[W3(1) W3(2)]
[W3(1) W3(2) W4(1)]
[W3(1) W3(2) W3(3) W3(4)]
14
[W4(6)]
[W3(3) W3(4)]
[W3(3) W3(4) W4(3)]
[W3(3) W3(4) W3(5) W3(6)]
15
[W4(7)]
[W3(5) W3(6)]
[W3(5) W3(6) W4(5)]
[W3(5) W3(6) W3(7) W3(8)]
16
[W4(8)]
[W3(7) W3(8)]
[W3(7) W3(8) W4(7)]
[W3(7) W3(8) W3(1) W3(2)],
wherein W1, W2, W3 and W4 comprise
W
1
=
DFT
8
×
8
W
2
=
P
T
⁡
[
D
1
0
0
D
1
]
⁢
P
,
⁢
where
⁢
⁢
D
1
=
DFT
4
×
4
W
3
=
P
T
⁡
[
D
2
0
0
D
2
]
⁢
P
,
⁢
where
⁢
⁢
D
2
=
diag
⁡
[
1
,
ⅇ
π
⁢
⁢
j
/
4
,
ⅇ
π
⁢
⁢
j
/
2
,
ⅇ
3
⁢
π
⁢
⁢
j
/
4
]
⁢
DFT
4
×
4
,
and
W
4
=
P
T
⁢
W
1
,
wherein it is P=[e1 e5 e2 e6 e3 e7 e4 e8],
wherein ek (1≦k≦8) is a unitary vector having a non-zero value for a k-th element,
wherein DFT4×4 and DFT8×8 comprise
DFT
4
×
4
=
1
4
⁡
[
1
1
1
1
1
j
-
1
-
j
1
-
1
1
-
1
1
-
j
-
1
j
]
and
DFT
8
×
8
=
1
8
⁡
[
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
0
w
1
w
2
w
3
w
4
w
5
w
6
w
7
w
0
w
2
w
4
w
6
w
8
w
10
w
12
w
14
w
0
w
3
w
6
w
9
w
12
w
15
w
18
w
21
w
0
w
4
w
8
w
12
w
16
w
20
w
24
w
28
w
0
w
5
w
10
w
15
w
20
w
25
w
30
w
35
w
0
w
6
w
12
w
18
w
24
w
30
w
36
w
42
w
0
w
7
w
14
w
21
w
28
w
35
w
42
w
49
]
where
,
⁢
w
=
ⅇ
-
2
⁢
πⅈ
8
,
respectively.

385 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/521,211Filed 12 Jan 2011 · us provisional application
Priority: KR 10-2011-000304612 Jan 2011
Published: US 2013/0129008 A123 May 2013
Granted: 3 Feb 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04B 7/0456
MIMO systems: selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
H04B 7/0469
Taking physical layer constraints into account: taking special antenna structures, e.g. cross polarized antennas into account
H04B 7/0473
Taking physical layer constraints into account: taking constraints in layer or codeword to antenna mapping into account
H04B 7/0478
Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting: special codebook structures directed to feedback optimisation